Since cows are fed via a pelleted feed offered in the robot during milking, feeding cows in box robotic dairies can be more expensive than feeding a total mix ration (TMR) in conventional farms.
A recent survey conducted by University of Minnesota researchers evaluated management factors associated with cow performance in robotic dairies. The survey included 33 dairies located in Minnesota and Wisconsin, and the amount of concentrate offered in the robots averaged 5.01 ± 0.84 kg/cow. The authors (Siewert et al., 2018) found that the amount of concentrate offered in the robot was positively associated with daily milk yield, with farms offering more concentrate generally obtaining more milk production.
It has been suggested that providing a greater quantity of concentrate within the robot increases milking frequency. Three studies conducted in the Rayner Dairy Research and Teaching Facility at the University of Saskatchewan (Saskatoon, SK, Canada) evaluated the effects of the amount of concentrate offered on cow performance, intake and milking activity:
- In the first study, the authors (Hare et al., 2018) fed 2 diets: a high-energy TMR with 0.5 kg of concentrate on a dry matter (DM) basis provided in the robot or a low-energy TMR with 5.0 kg of concentrate consumed in the robot. Total DM intake was 2.7 kg greater for cows fed the high-energy TMR (26.3 kg; 0.5 kg concentrate + 25.7 kg TMR) than the low-energy TMR (23.6 kg; 5.0 kg concentrate + 18.6 kg TMR). Milking frequency was not affected by treatment with cows attending the robot 3.0 times per day. Although milk production and milk composition were similar, cows receiving less concentrate in the robot gained more weight.
- In the second study, Menajovsky et al. (2018) evaluated the effects of the quantity of concentrate offered (2 vs. 6 kg) in both low- (54% forage) and high-forage diets (64% forage). Cows receiving more concentrate in the robot (6.1 vs. 2.0 kg/day) consumed less TMR in the feedbunk (21.4 vs. 24.9 kg/d); however, in this study total DM intake and milking frequency were not affected by treatment, averaging 27.3 kg/d and 3.6 times/d, respectively. Moreover, milk yield was similar (38.6 kg) regardless of concentrate supply in the robot or forage content in the diet.
- Finally, in the third study the researchers (Paddick et al., 2019) tested 4 concentrate amounts offered in the robot (0.50, 2.00, 3.49, and 4.93 kg of DM/day). Although intake of the TMR decreased linearly as the quantity of concentrate in the robot increased, total DMI intake was not affected by the amount of concentrate allocated in the robot, averaging 25.3 kg/d. Milking frequency (3.2 visits/d), milk yield (37.4 kg/d), milk fat (1.43 kg/d), and milk protein (1.22 kg/d) were not different among treatments.
In conclusion, the results of these works indicate that limiting the allocation of concentrate in the robot box does not affect cow intake, milk yield and milk components production, and voluntary attendance to the robot.